CVE-2021-1615Network attack vector

Remote service interruption via packet buffer exhaustion

Published Sep 23, 2021 · Updated Nov 7, 2024

Denial of service in Cisco IOS XE Embedded Wireless Controller Software allows remote attackers to interrupt AP and client traffic via crafted packets. The packet-processing path allocates insufficient buffer capacity for attacker-controlled traffic, allowing repeated packets to exhaust available resources. No authentication or user interaction is required; exploitation interrupts the affected AP and client traffic traversing it.

CVSS severity8.6
High
EPSS probability1.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco IOS XE Embedded Wireless Controller Software allows remote attackers to interrupt AP and client traffic via crafted packets. The packet-processing path allocates insufficient buffer capacity for attacker-controlled traffic, allowing repeated packets to exhaust available resources. No authentication or user interaction is required; exploitation interrupts the affected AP and client traffic traversing it.

The record

CVE
CVE-2021-1615
Published
Sep 23, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-410, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XE Softwareversion=n/a

Published CVSS scores

8.6Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-410Insufficient Resource Pool
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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